1. Field of the Invention
This invention relates to a device for clamping the split portion of a split heat-shrinkable sleeve which is used for covering the joint between the core wires in a communication cable.
2. Description of the Prior Art
When communication cables are joined together, the joint between their core wires is covered by a split heat-shrinkable sleeve.
A split heat-shrinkable sleeve is shown at 1 in FIGS. 1 and 2. It comprises a cylindrical body 3 formed from a heat-shrinkable synthetic resin, and lined with a layer 2 of polyamide, or the like. The cylindrical body 3 has a longitudinally extending split portion. A pair of longitudinally extending lugs or flanges 4 project outwardly from the edges of the split portion. One of the edges of the split portion has a tongue 5 which closes the split portion.
A pair of L-shaped clamping members 7 has hitherto been used for clamping the lugs 4 when the sleeve 1 is heated for shrinkage. Each lug 4 has a plurality of eyelet holes 6 spaced apart from one another by a distance of about 10 to 15 mm along its length, as shown in FIG. 1. Each L-shaped clamping member 7 has a plurality of elongated holes 8 (FIG. 3) which are alignable with the holes 6 of the lugs 4. An eyelet 9 is inserted in each aligned combination of holes 6 and 8 to hold the lugs 4 and the L-shaped members 7 together, as shown in FIG. 2. The eyelets 9 are squeezed and deformed by compression by a pair of pinchers 10 to force-fit the eyelets in the holes and, thus, clamp the lugs 4 together, as shown in FIG. 2.
The method as hereinabove described is very troublesome and inefficient, since a multiplicity of eyelets 9 must be squeezed and deformed by the pinchers 10, one by one.
The method is expensive, since it requires the L-shaped members, the eyelets and the pinchers, and since the L-shaped members and the eyelets are thrown away after the necessary work has been done. As the method does not employ any means for urging the opposing lugs against each other, it is difficult to ensure the intimate contact of the lugs when they have shrunk by heat. This results in the failure to achieve complete airtightness in the split portion.
A high degree of accuracy is required for the manufacture of the sleeve, since the eyelet holes 6 of the lugs 4 must be correctly spaced apart from one another so that they may be properly aligned with the elongated holes 8 of the L-shaped members 7. The sleeve is expensive to manufacture, since extra work is required for making the eyelet holes.